In Season 7, Episode 3 - Ourouboros we find out about Lister's parents.
Let's call the universe we see most often Universe A, and the other universe they encounter in that episode, Universe B:
- Kochanski B ends up stuck in Universe A
- Lister A and Kochanski B have a child
- Lister A goes back in time and places the child under a pool table.
- The child is Lister, forever looping his own time line.
The question is how did Lister B come to exist? Lister B is a hologram by this point anyway.
Is this just a plot hole?